The present invention relates generally to digital optical signal processing and more particularly to ultrafast digital optical signal processing using a Venn diagram based spatial encoding technique.
The following is a list of references pertinent to this invention.
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In order to form an optical digital computer, the implementation of an efficient optical binary full-adder is of particular importance. According to one proposed technique which is based on a half-adder approach, a three-input-variable optical full adder is decomposed into two or more two-input-variable optical gates. However, this scheme suffers from problems such as energy and speed loss through cascading, inefficient use of memory and so forth. According to another proposed technique, a single device-based direct optical full-adder implementation is utilized. Optical bistability is used to generate both sum and carry outputs from the three input bits to be added. However, because of direct counting of input power levels in an analog threshold operation the device output precision is strongly affected by the accuracy of input power levels as in the case of all analog devices. Still another proposed full-adder implementation approach suggests a polarization shadow casting scheme that allows for the simultaneous processing of all three input variables. The problem with this approach is the lack of an efficient real-time input encoding scheme.
From the above it can be concluded that an efficient optical full-adder requires that the following conditions should be satisfied:
1. All three input variables should be identically processed with the same nonlinear optical effect to reduce the possible scale mismatch of the device nonlinearities;
2. A serial connection of several optical gates should not be used unless the long existing problem of additional power and speed loss through device cascading can be solved;
3. A digital processing of all three variables should be performed so as to retain the computation accuracy; and
4. A real-time input encoding scheme must be used to possess an overall fast processing speed.
Accordingly, it is an object of this invention to provide a new and improved ultrafast digital optical signal processor.
It is another object of this invention to provide a new and improved ultrafast digital optical full adder.
It is still another object of this invention to provide a new and improved bit-serial opto-electronic central processing unit.